Question
my duck pond is turning green do you know of a safe product i can use they keep eating all plants i put in

Answer
Hi John,
Thanx for your question.  Does your duck pond have fish in it?  An easy way to control green water is to use barley bales.  They are about the size of a brick and are sunk in the bottom of the pond.  They have an agent in them the prevents algal bloom.  There are chemical compounds you can use but I do not recommend them because I try to stay away from chemicals.  You can find them at your DIY store or nursery.  I'd try the barley bale first.  Available at most places that sell watergardening accessories.  I hope this helps.
Tom